The present invention is directed to a load cell, in particular, a load cell for use in a net weigh filler machine. The net weigh filler machine is a conventional packaging machine.
The scale assembly or load cell of a net weigh filler is one of the most critical components. The scale is preferably highly sensitive to applied weight but relatively insensitive to lateral forces. It is desirable that the sensitivity to weight remain constant even after repeated use. It is also desirable to provide the scale with protection against breakage and permanent deformation in the case of an overload.
A conventional scale in a net weigh filler has a platform mounted on a post a few inches above the load cell with a bottle retainer attached to the top. The height of this scale assembly poses a problem. The leverage due to the physical positions will tend to amplify any lateral forces on the weighing platform and increase the chance of load cell damage. The single load cell is subjected to complex tortional forces when a weight is placed off-center on the weighing platform. This causes load errors in the weight reading. The load cell in the conventional scale has reduced thickness areas where it flexes. The bending radius in these areas is relatively small. This decreases the sensitivity of the cell.